I live in a hard water area and non use of the washers can result in the pump "furring" up.
Sharp tap may get it going again otherwise...new pump.
As always a bit of regular use always helps.
As for the dirty water....ugh! Very scary
Regards
Geof
Salmo, save the water from a dehumidifier to use in the washer bottle (I add a splash of methylated sprit)
